diff --git a/Modules/MitkExt/Algorithms/mitkSimpleHistogram.h b/Modules/MitkExt/Algorithms/mitkSimpleHistogram.h
index d089f3a05a..c07919851c 100644
--- a/Modules/MitkExt/Algorithms/mitkSimpleHistogram.h
+++ b/Modules/MitkExt/Algorithms/mitkSimpleHistogram.h
@@ -1,155 +1,162 @@
 /*=========================================================================
 
 Program:   Medical Imaging & Interaction Toolkit
 Language:  C++
 Date:      $Date$
 Version:   $Revision$
 
 Copyright (c) German Cancer Research Center, Division of Medical and
 Biological Informatics. All rights reserved.
 See MITKCopyright.txt or http://www.mitk.org/copyright.html for details.
 
 This software is distributed WITHOUT ANY WARRANTY; without even
 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 PURPOSE.  See the above copyright notices for more information.
 
 =========================================================================*/
 
 
 #ifndef MITKSIMPLEHISTOGRAM_H
 #define MITKSIMPLEHISTOGRAM_H
 
 #include "MitkExtExports.h"
 
 #include <mitkImage.h>
 #include <mitkWeakPointer.h>
 
 #include <itkImageRegionIterator.h>
 #include <itkImageRegionIteratorWithIndex.h>
 
 namespace mitk {
 
+
+//##Documentation
+//## @brief Abstract superclass for histograms with double values.
+//##        Classes which are deriving from this class can be cached
+//##        in the same way.
 class MitkExt_EXPORT SimpleHistogram
 {
 public:
 
+  /** @brief Returns the minimal value of the histogram. */
   virtual double GetMin() const = 0;
+  /** @brief Returns the maximum value of the histogram. */
   virtual double GetMax() const = 0;
-
+  /** @brief Creates a new histogram out the source. */
   virtual void ComputeFromBaseData( BaseData* source ) = 0;
+  /** @brief TODO: What should this method do?*/
   virtual float GetRelativeBin( double start, double end ) const = 0;
-
 };
 
 class MitkExt_EXPORT SimpleImageHistogram : public SimpleHistogram
 {
   public:
 
   SimpleImageHistogram()
   {
     valid=false;
     histogram=0;
   }
 
   ~SimpleImageHistogram()
   {
     if(histogram)
       delete histogram;
   }
 
   typedef itk::Image<short, 3>          CTImage;
   typedef itk::ImageRegionIterator< CTImage  > CTIteratorType;
   typedef itk::ImageRegionIteratorWithIndex< CTImage  > CTIteratorIndexType;
 
   typedef itk::Image<unsigned char, 3> BinImage;
   typedef itk::ImageRegionIterator< BinImage > BinIteratorType;
   typedef itk::ImageRegionIteratorWithIndex< BinImage > BinIteratorIndexType;
 
   typedef unsigned long CountType;
 
   protected:
 
   CountType *histogram;
 
   bool valid;
 
   int first;
   int last;
   int min;
   int max;
   CountType highest;
   double invLogHighest;
 
   public:
 
   double GetMin() const
   {
     if(!valid)
       return 0;
 
     return min;
   }
 
   double GetMax() const
   {
     if(!valid)
       return 1;
 
     return max;
   }
 
   void ComputeFromBaseData( BaseData* source );
   float GetRelativeBin( double start, double end ) const;
 
 };
 
 class MitkExt_EXPORT SimpleHistogramCache
 {
   public:
 
     static const unsigned int maxCacheSize = 64;
 
     class Element
     {
       public:
         mitk::WeakPointer<BaseData> baseData;
         itk::TimeStamp m_LastUpdateTime;
 
         virtual void ComputeFromBaseData(BaseData* baseData) = 0;
         virtual SimpleHistogram* GetHistogram() = 0;
     };
 
     typedef std::list<Element*> CacheContainer;
 
     CacheContainer cache;
 
     SimpleHistogramCache()
     {
 
     }
 
     ~SimpleHistogramCache()
     {
       TrimCache(true);
     }
 
     SimpleHistogram *operator[](BaseData::Pointer sp_BaseData);
 
   protected:
 
     void TrimCache(bool full=false)
     {
       unsigned int targetSize = full?0:maxCacheSize;
 
       while(cache.size()>targetSize)
       {
         delete cache.back();
         cache.pop_back();
       }
 
     }
 };
 
 }
 
 #endif // MITKSIMPLEHISTOGRAM_H